Centrifuge bucket



o. w. GREENE CENTRIFUGE BUCKET Filed Sept. 13. 1929- Oct. 13, 1931.

Inventor. Ol'wer` WAGE-eene,

l-ILS Attomgg.

Patented Oct. 13, 1931 UNITED STATES PATENT OFFICE OLIVER W. GREENE, F PITTSFIELD, MASSACHUSETTS, ASSIGNOB T0 GENERAL Elm TRIC COMPANY, A CORPORATION 0F NEW YORK CENTRIIUGE BUCKET Application filed September 18, 1929. Serial No. 892,415.

The present inventon relates to centrifuge buckets such as are used in the manufacture of rayon, for example. Such buckets are mounted on'a vertical shaft, usuall the shaft of an electric motor, and are requlred to rotate at a high speed. Buckets of the constructions now in use are capable of operating at speeds of the order of 7,500 R. P. M.,

. and in some instances at speeds as high as 10,000 R. P. M. However with the demand for finer twisted rayon, there are required centrifuge buckets capable of operating at speeds substantially greater than those heretofore used, and the primary object of my 16 invention is to provide an improved centrlfuge bucket which is capable of operating at such higher s eeds.

A further o ject of my invention is to provide an improved construction and arrange- 20 ment for holding the 'cover of a centrifuge bucket in position.

For a consideration of what I believe to be novel and my invention, attention is directed to the following specification and the claims appended thereto:

In the drawings, Fig. 1 is a side elevation of a centrifuge bucket embodying my invention, and Fig. 2 is a transverse sectional view thereof. l

According to my invention I` form the lower portion l of the bucket from a suitable molding- Icompound, such as a resinous compound which is converted by heat or by heat and pressure into an-infusible insoluble state,-`

and a suitable filling substance, such as wood pulp, but instead of forming the upper portion of this same material, I construct such upper portion 2 of a substantially stronger material, as hereinafter described, and make the upper port-ion relatively thin. In additerial `to the lower portion of the bucket as is indicated at 3 for the purpose of making the moment of inertia about the vertical axis greater than the moment of inertia about the horizontal axis through the center of gravity of the bucket. In Fig. 2, the horizontal axis through the center of gravity of the bucket is indicated at C. By making the upper por n tion of the bucket of relatively thin strong tion to the foregoing, I add additional ma-v material, andby adding material at the lower portion of the bucket, I am enabled tol so. distribute the material in the bucket as to make the moment of inertia about the vertical axis suiiciently greater than the moment of inertia ,about the horizontal axis through the center of gravity of the bucket that the bucket is stable at high speeds even though it is slightly out of balance due either to its inherent structure or to the material in it. At the same time, the upper' portion or rim of the bucket is strong enough to withstand the high centrifugal stresses to which it is subjected. Y

In carrying out my invention, I form the upper portion of the bucket from twisted spinnable fibers, such as hard twisted cotton or linen cord united by a resinous compound which is converted by heat or by heat and pressure into an infusible, insoluble state. The cord may be wound to the desired shape on a form rior to molding, and then placed in the molfin which the bucket is to be made. As a resinous compound I use preferably a phenolic condensation product.

The driving plate for the bucket is indicated at 4, the seat for the bucket being indicated at 5, and the driving stem at 6. 7 is the driving shaft which may be, for example, the shaft of an electric motor. It has a slight taper as does also the opening through stem 6 with which it forms a driving connection. The bucket is provided with a bushing 8 which may be made of bronze or other suitable material, and in which stem 6 fits. To permit of the ready removal of bushing 8, I provide opposed recesses 9 in the lower lend of the bucket through which the hooks of a suitable bushing puller may be inserted to engage in a groove 10 in the bushing. 11 indicates the openings in the bucket through which liquid is discharged.

If found desirable, I may provide rein forcing means for the peripheral portion of enlargement 3, and in the drawings (Fig. 2) such a reinforcing means is indicated at 12, it being indicated in the form of lcord material surrounding and forming a part ofv such peripheral portion.

The cover of the bucket is indicated at 13,

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naeacee and for holding it in place against its seat 'extending cord of twisted fibers united by a.

which) lits in a' groove 16 formed in .the bucket wall just above the cover. With this arrange-` ment, when the bucket is rotating, the` rubberring expands'tightly into the groove due to centrifugal force, and holds the cover tightly in. place. For high speed work, the bucket must be nicely balanced, and the higher the speed the better must be the balance. A slight amountgof unbalance at the rim especially has an adverse eifect on the running. The use of a rubber ring for holding the cover in place has the advantage that it is fairly rovide a relatively soft rubber ring 15 resinous compound.

' ln w1tness whereof hand this 11th da light in weight, uniform'in structure, and

expands evenly all around 'under the action of centrifugal force, so that it does not alfect adversely the balance at high speed.

I have described what Inow regard as the preferred form of my invention. It is to be understood, however, that this is only one structural example of my invention and that it may be carried out by other means, such als come within the scope of the appended c alms.

VVhat` I claim as new and desire to secure by Letters Patent of the United States, is:

l. A molded centrifuge bucket having its upper portion formed of circumferentially extending cord of twisted spinnable fibers l united by a resinous compound.

2. A molded centrifuge bucket having its lower portion formed from a molded substance comprising a resinous compound and a filling substance, and its upper portion formed of hard twisted cord wound circumferentially. 1

3. A molded centrifuge bucket having its lower portion formed from` a molded substance comprising a resinous compound and a filling substance and its upper portion formed from twisted spinnable fibers united by a resinous compound, the material in said bucket being so distributed that the'moment of inertia about the vertical axis is 'greater than the moment of inertia about the horizontal axis through the center of gravity'of the bucket.

4. A molded centrifuge bucket having its lower portion formed from a molded substance comprising a resinous compound and a filling substance and its upper portion formed from circumferentially extending twisted spinnable fibers united by a resinous compound, the material in said bucket being 5. A vmolded centrifuge bucket at least a extending cord of twisted fibersunited by a resinous compound.

6; A molded centrifuge bucket the upper i portion of which comprises circumferentially I have hereunto setmy Se tember, 1929. LIVE .W. GREENE.l

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